Randy Pench/ rpench@sacbee.com

Bill O’Brien, an inspector with the California Air Resources Board, places a sticker on the windshield of a truck after it passed inspection on southbound Highway 99 north of west Riego Road on Tuesday, September 17, 2013 in Sacramento, Calif. Truck inspectors with the California Air Resources Board conduct inspections of heavy-duty trucks along Highway 99 to check for compliance with state air pollution laws.

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